Ok so the new Powerbook come out today and I'm wanting to get one at the end of this week. I had a look at the upgrades that you can do on it and I'm a little puzzled. In all true mac-forums style I trust that someone can help me out.

Should I get the
-120Gb at 5400rpm or
-100Gb at 7200rpm?

What I'm really wanting to know is will I benefit more from 20 more Gb or more speed? I’m slamming 2Gb or Ram in there so that isn't a limiting factor for the speed.

IMO,. battery life takes a hit at 7200rpm. 5400rpm is pretty darn fast for a small hard drive. I'd go for the 120gig over the 100gig because it'll be a fast disk as it stands and you get 20gb more space.

When it comes to a laptop 100GB of space is more than enough for what most people are doing. If you need more space you are probably doing something more demanding that requires a desktop. Because of that I don't think space is really an issue. Of greater concern would be the battery life. While a 7200rpm drive isn't going to drain your battery, it may cut the total amount of time you can run the system by a bit. It wouldn't be anymore than around 30 minutes. The 7200rpm drive will also offer you noticeable better system responsiveness. If it was me, I'd go with the 100GB 7200rpm drive.